Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, digital cameras, digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, video teleconferencing devices, and the like. Digital video devices implement video compression techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263 or ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), and extensions of such standards, to transmit and receive digital video information more efficiently.
Video compression techniques perform spatial prediction and/or temporal prediction to reduce or remove redundancy inherent in video sequences. For block-based video coding, a video frame or slice may be partitioned into macroblocks. Each macroblock can be further partitioned. Macroblocks in an intra-coded (I) frame or slice are encoded using spatial prediction with respect to neighboring macroblocks. Macroblocks in an inter-coded (P or B) frame or slice may use spatial prediction with respect to neighboring macroblocks in the same frame or slice or temporal prediction with respect to other reference frames.
After video data has been encoded, the video data may be packetized by a multiplexer for transmission or storage. MPEG-2 includes a “Systems” section that defines a transport level for many video encoding standards. MPEG-2 transport level systems may be used by MPEG-2 video encoders, or other video encoders conforming to different video encoding standards. For example, MPEG-4 prescribes different encoding and decoding methodologies than those of MPEG-2, but video encoders implementing the techniques of the MPEG-4 standard may still utilize the MPEG-2 transport level methodologies. In general, references to “MPEG-2 systems” refer to the transport level of video data prescribed by MPEG-2. The transport level prescribed by MPEG-2 is also referred to in this disclosure as an “MPEG-2 transport stream” or simply a “transport stream.” Likewise, the transport level of MPEG-2 systems also includes program streams. Transport streams and program streams generally include different formats for delivering similar data, where a transport stream comprises one or more “programs” including both audio and video data, while program streams include one program including both audio and video data.
The MPEG-2 Systems specification describes how compressed multimedia (video and audio) data streams may be multiplexed together with other data to form a single data stream suitable for digital transmission or storage. The latest specification of MPEG-2 systems is specified in “Information Technology—Generic Coding of Moving Pictures and Associated Audio: Systems, Recommendation H.222.0; International Organisation for Standardisation, ISO/IEC JTC1/SC29/WG11; Coding of Moving Pictures and Associated Audio,” May 2006. MPEG recently designed the transport standard of MVC over MPEG-2 systems and the latest version of this specification is “Study of ISO/IEC 13818-1:2007/FPDAM4 Transport of MVC”, MPEG doc. N10572, MPEG of ISO/IEC JTC1/SC29/WG11, Maui, Hi., USA, April 2009.